Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada.
Delsys & Altec Incorporated, Natick, MA, USA.
Eur J Appl Physiol. 2021 Sep;121(9):2393-2411. doi: 10.1007/s00421-021-04700-w. Epub 2021 May 8.
Physical performance fatigue can be ascribed to both peripheral and central components. Central fatigue, however, is an elusive entity, consisting of cognitive/sensory component and presumably also a neuro-physiological component that are difficult to tease apart and assess independently of each other. The most widely accepted method for the assessment of central fatigue is based on the premise that decreasing volitional muscle activation (VA), as determined by the interpolated twitch technique (ITT) in fatiguing muscles, reflects increasing central fatigue. Suffering its own shortcomings, the validity of VA determination under fatigued conditions has never been proven and is only assumed. This review presents evidence that questions ITT's reliability and validity in reflecting VA in the fatiguing muscle and, consequently, VA's validity for central fatigue assessment. Specifically highlighted is the paradox of children and endurance athletes, who share striking endurance characteristics, being claimed as more centrally fatigable than untrained adults. Further research and new directions are needed for confirming and quantifying central fatigue and teasing apart its psychologic and neuromotor components.
体力疲劳可归因于外周和中枢成分。然而，中枢疲劳是一种难以捉摸的实体，它由认知/感觉成分组成，可能还有神经生理成分，这些成分很难相互分离和独立评估。评估中枢疲劳最广泛接受的方法基于这样一个前提，即通过疲劳肌肉中的插值抽搐技术 (ITT) 确定的意志肌肉激活 (VA) 减少反映出中枢疲劳增加。VA 在疲劳条件下的测定有其自身的局限性，其有效性从未得到证实，只是假设。本综述提供的证据质疑 ITT 在反映疲劳肌肉中 VA 的可靠性和有效性，因此 VA 对中枢疲劳评估的有效性。特别突出的是儿童和耐力运动员的矛盾之处，他们具有惊人的耐力特征，被认为比未经训练的成年人更容易出现中枢疲劳。需要进一步的研究和新的方向来确认和量化中枢疲劳，并分离其心理和神经运动成分。
